wood chemistry
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Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Carsten Mai ◽  
Uwe Schmitt ◽  
Peter Niemz

Abstract Wood science covers in particular the areas of the formation and composition as well as the chemical, biological and physical-mechanical properties of wood. First comprehensive studies have already been published in the last century. Detailed knowledge of wood is required for the processing of wood, the production of wood-based materials, and the utilization of wood and wood-based materials as buildings and various other products such as furniture. This review gives a brief overview on the progress in wood chemistry, wood biology (including photosynthesis and biodeterioration), and physical-mechanical properties of wood and wood-based materials. These fundamentals are also essential for understanding technological processes and product development.


2021 ◽  
Vol 25 (3) ◽  
pp. 126-141
Author(s):  
G.N. Kononov ◽  
◽  
A.N. Zarubina ◽  
A.N. Verevkin ◽  
V.D. Zaytsev ◽  
...  

The article is devoted to the history of pyrogenetic wood processing. The stages of development of this branch of wood chemistry from ancient times to our time are considered. The features of the technologies of pit, heap and fire coal burning are described in detail. Considered are the schematic diagrams of batch and continuous charcoal kilns, as well as modern retort technologies for pyrolysis of wood and waste of its mechanical and chemical processing. This article is the third in the series «Wood as a chemical raw material — history and modernity», the first and second were published in the journal «Forestry Bulletin», volumes 24, № 1 and № 5.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 372
Author(s):  
Emil Engelund Thybring ◽  
Maria Fredriksson

Moisture plays a central role in the performance of wood products because it affects important material properties such as the resistance to decomposition, the mechanical properties, and the dimensions. To improve wood performance, a wide range of wood modification techniques that alter the wood chemistry in various ways have been described in the literature. Typically, these modifications aim to improve resistance to decomposition, dimensional stability, or, to introduce novel functionalities in the wood. However, wood modification techniques can also be an important tool to improve our understanding of the interactions between wood and moisture. In this review, we describe current knowledge gaps in our understanding of moisture in wood and how modification has been and could be used to clarify some of these gaps. This review shows that introducing specific chemical changes, and even controlling the distribution of these, in combination with the variety of experimental methods available for characterization of moisture in wood, could give novel insights into the interaction between moisture and wood. Such insights could further contribute to applications in several related fields of research such as how to enhance the resistance to decomposition, how to improve the performance of moisture-induced wooden actuators, or how to improve the utilization of wood biomass with challenging swelling anisotropy.


Soil Systems ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 26 ◽  
Author(s):  
Sossina Gezahegn ◽  
Mohini Sain ◽  
Sean Thomas

Chars intended for use as soil amendment (“biochars”) vary greatly in their chemical and physical properties. In the present study, 19 Canadian temperate wood feedstocks were charred across a range of pyrolysis temperatures from 300–700 °C. The resulting 95 biochars were tested for their physio-chemical properties and liming capacity. Data indicated increasing base cation concentrations including Ca, Mg, and K (elements that characteristically form liming compounds, i.e., carbonates) as pyrolysis temperature increased. Acidic surface functional groups were analyzed with modified Boehm titration: Carboxylic and lactonic functional group concentrations decreased and phenolic group concentration increased with pyrolysis temperature. Functional group composition also varied greatly with feedstock: In particular, conifer-derived biochars produced at pyrolysis temperatures <500 °C showed much higher carboxylic and lactonic functional group concentrations than did angiosperm-derived biochars. Liming capacity was assessed using soil incubation experiments and was positively related to biochar pH. Both acidic surface functional group concentration and nutrient element concentration influenced biochar pH: we developed a non-linear functional relationship that predicts biochar pH from the ratio of carboxylic to phenolic moieties, and concentrations of Ca and K. Biochar’s liming components that are inherited from feedstock and predictably modified by pyrolysis temperature provide a basis for optimizing the production of biochar with desired pH and liming characteristics.


Author(s):  
Е.Н. Наквасина ◽  
А.В. Воеводкина ◽  
А.Г. Волков

При изреживании древостоев в результате рубок ухода в насаждении происходят изменения не только в таксационных показателях древесных пород, но и в эколого-ценотической обстановке насаждений, пройденных рубками, что сказывается на формировании верхних горизонтов почв. Исследования проводились на стационарных объектах, заложенных в 1959 г. Архангельским институтом леса и лесохимии (Северный НИИ лесного хозяйства) в Северном участковом лесничестве Обозерского лесничества Архангельской области, которое относится к северотаежному району европейской части Российской Федерации. В сосново-березовом молодняке чернично-брусничного типа леса с составом 6С4Б+Ос (возраст 13 лет) заложено три варианта рубок ухода с различной выборкой по числу деревьев. Первый вариант – двухприемная рубка ухода с интервалом 27 лет, с интенсивностью выборки в первый прием 36% по числу деревьев, во второй прием 30% по запасу; в настоящее время состав 10С, число деревьев составляет 837 экз./га. Два других варианта – одноприемные рубки с интенсивностью изреживания 76 и 84%; в настоящее время состав 10С, густота насаждений составляет 894 и 596 экз./га соответственно. Контролем служила площадь, не пройденная рубками ухода. Изучены физико-химические свойства верхних (подстилочный и подзолистый) горизонтов альфегумусовых почв в сформированных приспевающих сосняках, в том числе мощность горизонтов, плотность их сложения, реакция среды, содержание органического вещества, углерода и гумуса, подвижных форм фосфора и калия. Определен запас подстилочно-торфяного горизонта. Установлено, что в результате изреживания древостоев большим изменениям подвержен горизонт О, играющий буферную роль в лесных биогеоценозах. В результате действия комплекса эколого-ценотических факторов увеличиваются его мощность, плотность сложения и запас, содержание органического вещества. Все это сказывается на нижележащем подзолистом горизонте, в котором содержание органических компонентов увеличивается в 2–3 раза, по сравнению с контролем. Это приводит к усилению оподзоливания, что проявляется в увеличении мощности подзолистого горизонта. Меньшее влияние на оподзоливание оказали двухприемные рубки, которые по комплексу воздействия на физико-химические свойства верхних горизонтов почв можно считать более благоприятными с точки зрения воздействия на экологическую среду формирующихся насаждений после проведения рубок ухода. Thinning is influence to ecological-cenotic condition that affects the formation of the lower tiers of the forest ecosystem. The research was conducted on stationary objects that created in 1959 by Arkhangelsk's Institute of Forest and Wood Chemistry (now North research institute of forestry). There are 3 variants of thinning with different sample by number of tree trunks in pine-birch forest with whortleberry-clusterberry cover. The first variant is two-stage thinning with 27 years interval and intensity of cutting in the first reception of 36% in the number of trees, in the second reception 30% in stock. At the moment there is 100% pine stocking with 837 trunks at hectare. Other two variants are one-stage thinning with intensity of cutting equal 76 and 84%. At the moment its 100% pine stocking with 894 and 596 trunks at hectare. Reference is not thinning forest. We studied chemical and physical properties topsoil (O and E) of podzols, such as: thickness, density, pH, organic carbon, humus and mobile forms of P2O5 and K2O.We evaluated weight of forest litter (O) and detect its significant changes as results of thinning. Under the influence of ecological-cenotic factors grow litter forest thickness, density, weight and organic carbon. This affects to albic horizon that organic carbon grow at 2–3 times compared reference. Less influence to soil and forest litter has two-stage thinning.


2018 ◽  
Vol 625 ◽  
pp. 220-232 ◽  
Author(s):  
Andrea Hevia ◽  
Raúl Sánchez-Salguero ◽  
J. Julio Camarero ◽  
Allan Buras ◽  
Gabriel Sangüesa-Barreda ◽  
...  

2018 ◽  
Vol 68 (1) ◽  
pp. 78-85 ◽  
Author(s):  
Qingzheng Cheng ◽  
Chengfeng Zhou ◽  
Wei Jiang ◽  
Xiping Zhao ◽  
Brian K. Via ◽  
...  

Abstract The mechanism underlying thermal degradation of oriented strand board was tested under a humid environment. Near-infrared reflectance (NIR) spectroscopy coupled with chemometric modeling was utilized to better understand the degradation of functional groups over time. The flexural properties, internal bond (IB), water absorption, and thickness swelling were tested after exposure to various times of 0, 3, 6, and 9 weeks in a climate-controlled laboratory to 76.7°C and 60 percent relative humidity. The largest reduction in all flexural and physical properties occurred during the first 3 weeks of exposure and then leveled off thereafter, while IB decreased significantly through the 9-week period (α = 0.05). Chemometric models built from NIR spectra revealed pertinent chemical changes in wood chemistry and resin components.


2017 ◽  
Vol 51 (3) ◽  
pp. 475-492 ◽  
Author(s):  
Charles Essien ◽  
Brian K. Via ◽  
Qingzheng Cheng ◽  
Thomas Gallagher ◽  
Timothy McDonald ◽  
...  

Author(s):  
Л.П. Рощевская

На основе архивных документов впервые реконструированы причины возникновения, результаты деятельности, штаты технологической лаборатории химии древесины Базы АН СССР по изучению Севера в г. Сыктывкар Коми АССР в 1941 г. Сотрудники лаборатории исследовали промышленные установки и условия переработки смоло-скипидарного сырья, которое в те годы считалось одним из источников получения камфоры, моторного топлива и смазочных масел, а также взрывчатых веществ. Показано, что центром исследований химической обработки древесины был Всесоюзный НИИ сульфатно-спиртовой и гидролизной промышленности в Ленинграде. В годы Великой Отечественной войны в Сыктывкаре оказались крупные ученые и специалисты, под руководством которых производилась важнейшие исследования оборонного характера. Установлено, что перед сотрудниками лаборатории химии древесины в Сыктывкаре в годы войны были поставлены задачи: выявить и охарактеризовать минеральное и растительное сырье, необходимое для нужд обороны страны; разработать методику получения моторного топлива и смазочных масел, изготовленных на местах из недефицитного сырья. В лаборатории производили важнейшие исследования оборонного характера, трудились крупные деятели науки и производства. Руководителями коллектива были эвакуированные в Сыктывкар будущий член-корреспондент АН СССР профессор Д.Н. Курсанов и лауреат Сталинской премии М.А. Грехнев, который доказал, что в Коми АССР целесообразнее использовать для получения терпентинового масла сосну. Сотрудники изучали технологический процесс получения смолы и скипидара. На основании этих научных выводов в республике было на период войны сохранено и получило дальнейшее развитие смоло-скипидарное производство. Основой для таких разработок была местная деревообрабатывающая промышленность. Показаны условия труда и быта сотрудников лаборатории в годы войны. Высказаны предположения о причинах закрытия лаборатории химии древесины в 1946 г. On the basis of archival documents causes of establishment, results of activities, staff of the technological laboratory of wood chemistry of the Base of the USSR Academy of Sciences for the Study of the North in Syktyvkar, Komi ASSR in 1941 are reconstructed for the first time. The staff of the laboratory investigated industrial facilities and conditions for processing resin and turpentine raw materials which at that time was considered one of sources for obtaining camphor, motor fuel and lubricating oils as well as explosive materials. The centre of investigations of chemical wood processing was All-Union Scientific Research Institute of sulphate-spirit and hydrolysis industry in Leningrad. During the Great Patriotic War prominent researchers and experts worked in Syktyvkar. Under their leadership the most important research of defensive nature was conducted. It was found that during the war before the staff of the laboratory of wood chemistry in Syktyvkar were set tasks to identify and characterize mineral and vegetable raw materials required for defense needs of the country, to develop a method of producing motor fuels and lubricating oils, made of local non-deficient raw materials. The laboratory produced the most important research of defensive nature, major figures of science and industry worked there. The leaders of the team were evacuated to Syktyvkar future corresponding member of the USSR Academy of Sciences professor D.N. Kursanov and Stalin Prize winner M.A.Grehnev who proved that in the Komi ASSR pine should be used for obtaining turpentine oil. The staff studied the technological process of producing resin and turpentine. On the basis of these scientific conclusions during the war resin and turpentine manufacture in the Republic was further developed. The basis for these developments was the local woodworking industry. The work and living conditions of the laboratory staff during the war are presented. Assumptions are made about the reasons for the closure of the laboratory of wood chemistry in 1946.


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